Did you hear? Samoa Air is adding something new to its aircraft - couches! Well, sofa-like seating anyway, but before you get all excited, the tiny airline (three planes) isn't doing it out of the goodness of its heart.

It's sheer necessity. Many Samoa Air passengers are reportedly in the heavyweight class and even the airline's CEO notes "some [customers] top out at 460 pounds." When it comes to airfare, passengers pay what they weigh, and that adds up.

So does the premium U.S. airlines slap on airfare during summer vacation season. The fares are high because airlines know we'll pay; it's when we want to fly. Blame it on tradition, blame it on kids are out of school.

However, these uber-prices can be too rich for some. I've even heard from a few folks who are once again thinking in terms of stay-cations. If that's you, don't give up. Not when you can save up to a third on summer airfare.

It's all in the timing. Timing has a lot to do with the airlines' definition of summer. As far as they're concerned, summer is done, dead, kaput by late August. The governing factor: that's when kids go back to school.

Let me give you two examples showing how, if you can move your flights around a little - in some cases it's just a matter of a few days - you could save a bundle.

Example No. 1 - Domestic flight

First, let's consider a long haul flight, such as Los Angeles to New York. I checked prices recently, and here is what I found:

• Round-trip airfare price for 7-day trip, departing Aug. 12 - $536

• Same trip, departing Aug. 26 - $401

• Percentage saved with later departure - 33 percent

Please note that since airline prices are constantly changing, you may not get the same results by the time you read this, but chances are good you will come close.

For medium-length flights such as Chicago to Philadelphia, I saw savings of about 25 percent; on short hauls, such as San Francisco to L.A., savings of close to 20 percent. You can often find similar saving on trans-Atlantic flights, too.

Example No. 2 - Europe flight

See the difference just a couple of weeks makes when it comes to a flight from Chicago to Frankfurt.

• Round-trip airfare price for 7-day trip, departing Aug. 12 - $1,545

• Same trip, departing Aug. 26 - $1,157

• Percentage saved with later departure - 33 percent

Savings vary. Let's say you push back a flight from Washington, D.C., to Paris by the same number of days. This will save you money, about 25 percent and that extra $300 in your pocket can buy an awful lot of bonbons de chocolat in the City of Lights.

Can't schedule your entire trip that late in the season? Split the difference. Start your travel at during the peak of the summer but return past-the-peak of the season and you'll still reap half the savings.

If you're totally flexible and can forgo a summer trip, you'll see all kinds of discounting and specials throughout the fall. Plus you'll enjoy cooler temperatures (it can get pretty humid in Barcelona in summer, and that goes double for Miami). Even better, there will be fewer crowds, at the airport and at popular attractions. Spring is cheaper as well, but winter is cheapest of all (exceptions: Thanksgiving and Christmas holiday periods).

Oh, remember how I mentioned those chocolate bonbons? Try to resist if you'll be flying Samoa Air anytime soon.

The opinions expressed by Rick Seaney are his alone and not those of ABC News.